code: def test_CSVIter(tmpdir):
      def check_CSVIter_synthetic(dtype="float32"):
          data_path = os.path.join(str(tmpdir), "data.t")
          label_path = os.path.join(str(tmpdir), "label.t")
          entry_str = "1"
          if dtype is "int32":
              entry_str = "200000001"
          if dtype is "int64":
              entry_str = "2147483648"
          with open(data_path, "w") as fout:
              for _ in range(1000):
                  fout.write(
                      ",".join([entry_str for _ in range(8 * 8)]) + "\n"
                  )
          with open(label_path, "w") as fout:
              for _ in range(1000):
                  fout.write("0\n")
  
          data_train = mx.io.CSVIter(
              data_csv=data_path,
              data_shape=(8, 8),
              label_csv=label_path,
              batch_size=100,
              dtype=dtype,
          )
          expected = mx.nd.ones((100, 8, 8), dtype=dtype) * int(
              entry_str
          )
          for _ in iter(data_train):
              data_batch = data_train.getdata()
              assert_almost_equal(
                  data_batch.asnumpy(), expected.asnumpy()
              )
              assert (
                  data_batch.asnumpy().dtype == expected.asnumpy().dtype
              )
  
      for dtype in ["int32", "int64", "float32"]:
          check_CSVIter_synthetic(dtype=dtype)
  
imports: import mxnet
  import mxnet.ndarray
  from mxnet.test_utils import *
  from mxnet.base import MXNetError
  import numpy
  import os
  import gzip
  import pickle
  import time
  import sys
  from common import assertRaises
  import pytest
  from itertools import zip_longest
label_desc: Use image node_id 16 for calling a global function with example usage: test_CSVIter(tmpdir) without return types